I thinking (a guess) that sip and pjsip settings are completely different so my 'fromdomain' change should not have effect for pjsip.
Output from 'head -5 /etc/asterisk/sip.conf' gives:
;--------------------------------------------------------------------------------;
; Do NOT edit this file as it is auto-generated by FreePBX. All modifications to ;
; this file must be done via the web gui. There are alternative files to make ;
; custom modifications, details at: http://freepbx.org/configuration_files ;
;--------------------------------------------------------------------------------;